Composition of matter for deadening partitions, floors, and the like



-' titions, Floors, and the like,

UNITED STATES PATENT OFFICE.

HARRY B. DAVIS,

OF CHICAGO, ILLINOIS, ASSIGNOR- .OF ONE-FOURTH TO DR. BERT H.

KERSHAW, AND ONE-FOURTH T MILES L. WHITNEY, BOTH OF CHICAGO, ILLINOIS.

COMPOSITION OF MATTER FOIR. DEADENING PAIRTITIONS, FLOORS, AND THE LIKE.

No Drawing.

To all whom it may concern:

, Be it known that I, HARRY B. DAVIS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Composition of Matter for Deadening Parof which the following is a specification.

The principalobject of my invention is to provide a material which may be used in the making of tone chambers for phonographs. As is well understood, the purpose of the phonograph amplifying horn or tone chamber is to.,act as a neutral and faithful conveyor of sound, and-in no way to add to, or

. diminish,- or cause to be lost any of the origia material that sium oxide,

nal tone waves as they issue from the reproducer. The material used in the construction of the tone. chamber should be of an in-- ert character so designed as not to respond to vibrations impressed upon it, and should be a material as near neutral as possible. It is with this purpose in mind to provide such have directed my attention to this particular art.

A further object of my invention is to rovide such deadening material for use for t e many various purposes to which it may be applied, for instance, such as making sound proof telephone booths, or the like, deadening floors so that sounds would notgo through from one story in a building to another, deadening partitions for various purposes, and for similar objects. My composition consists of a mixture of ground cork, asbestos, ground siIica,.ma ne and magnesium chloride, t ese Specification of Letters Patent. Patented Feb, 14 1922,

Application filed October 28, 1920.. Serial No. 420,275.

parts being mixed in a plastic substance part ground silica; two and one half parts magnesium oxide; and magnesium chloride sufiicient to form the desired consistency in the mixture.

The consistency of the mixture may be varied to suit the specific purpose or the person, or the parts comprising the mixture may vary to slight degrees without affecting the result or my invention.

My composition is, as before stated, molded for the purpose desired, and is found most efiicient as a deadening material, and to possess a great efficiency for the formation of tone chambers for phonographs, for the sounds emanating therefrom have been shown to be much more true and perfect in every respect than from the tone boxes that are in use.

Having thus described my invention, what I claim to secure by Letters Patent of the United States is: a I

A composition of matter adapted to form tone boxes for phonographs, comprising four parts ground cork, one part asbestos, one part ground silica, two and one half parts magnesium oxide, and magnesium chloride, substantially as described.

In testimony whereof, I have signed the foregoing specification.

HARRY B. DAVIS. 

